The broad objectives of this project are to understand the processes of visual detection, recognition, and perception in humans and to understand how visual information is dealt with in the brain. The experimental techniques will be the performance of visual psychophysical experiments on human subjects. The basic approaches will be (1) finding the physical limits and statistical properties of detection and recognition and (2) correlating known neurophysiological results with psychophysical findings obtained from this project. Hopefully this will lead to a further understanding of the underlying physical and neural activity of various visual tasks both for normal vision as well as for certain visual defects. BIBLIOGRAPHIC REFERENCES: Sakitt, B. Psychophysical Correlates of Photoreceptor Activity. Vision Research, 16, 129 (1976). Sakitt, B. Locus of short term visual storage. Science, 190, 1318 (1975).